Regulating mechanism for steam-generating plants



NOV. 5, 1929. wlENER 1,734,702

REGULATING MECHANISM FOR STEAM GENERATING PLANTS Filed July 15; 1922 2Sheets-Sheet l J. A. WIENER Nov. 5, 1929.

REGULATING MECHANISM FOR STEAM GENERATING PLANTS Filed July 15. 1922 2Sheets-Sheet 2 patented Nov. 5, 192

UNITED STA JOHN A. WIENEB, F ROTHSCHILD, WISCONSIDT BEGULATII'I'GMECHANISM FOR STEAM-GENERATING PLANTS Application filed July 15, 1922.Serial No. 575,361.

. In most plants making use of steam generators, the demand for steamvaries widely t and often irregularly. The attempts of the. boiler roomattendant to regulate the supply of fuel and air'and feed water inaccordance with the demand for steam are little better than guess workbecause ordinarily they have no indication of the demand being made uponthe boiler except by changes in the steam pressure gauge. There are somedevices which will give an, indication of the rate of flow of steam fromthe boiler and so assist in governingthe management of the fire. Thesedevices, however, call for intelligent interpretation of theirindications and are not of I much useto the ordinary boiler attendantforthis reason.

It is an object of the present invention to make use of an indicatingdevice of the class just mentioned for automatic control of the supplyof fuel, air and feed water so that proper condition of the fire at alltimes may e easily maintained.

It is a further object of this invention to provide an automatic systemby which the re in the generating plant may at all times be kept in acondition corresponding tothe demand for steam.

It is a further object of this invention to provide a number of electricmotors for moving regulating devices for controlling the steamgenerating plant and to control said motors by an indicating devicewhich is responsive to the demands made upon the boiler.

It is a further object of this invention to utilize the moving parts ofan indicating device to control the movement of motors which shalladjust the conditions at the boiler in accordance with the conditionsindicated by the indicating device. I

Otherand further important objects of this invention will be apparentfrom the'disclosures in the accompanying drawings and the followingspecification.

The invention (in a preferred form) is illustrated in the drawings: andhereinafter more fully described.

On the drawings Figure 1 is a diagrammatic view of a boiler showing theapplication of the regulating motors thereto.

Figure 2 is a diagram of the electrical connections.

Figure 3 isa View of the driving and contacting. mechanism. Figure 4 isa perspective view of the contacting mechanism.

As shown on the drawings:

There is indicated at 1 a device for interpreting the condition of thesteam in terms of electrical resistances. As the details of this deviceare not in themselves any part of my invention, the description thereofwill be limited to what is necessary in order to make the invention ofthis application readily understood. The instrument 1 is of an, elbowshape and has connections 2 and 3 leading to the ends of an oblique tube4. A thread of mercury extends along this tube, standing'at a heighttherein coresponding to the difference in pressure between the two endsthereof. As steam flows through the elbow l a difference in pressure iscreated between connections 2 and 3 and the end of the thread of mercuryin the tube 4. moves correspondingly. An electrical resistance 5 isconnected at various points to the interior of the tube '4 so that theposition of the mercury by shunting a larger or smaller portion of thisresistance translates the difference in steam pressure into anelectrical resistance. The position of the mercury in the tube 4, and sothe resistance 5, corresponds therefore to the quantity of steam beingused.

The elbow 1 also has a connection to a manometer 6 in which, in asimilar way, the

pressure of the steam is made to show as an electrical resistance. Theelbow 1 also contains a plug inserted at 7 by means of which any form ofresistance thermometer may be used to indicate the temperature of thesteam in terms of an electrical resistance. The difference in pressurebetween the connections 2 and 3 is a direct function of the velocity ofthe steam through the elbow 1. The resistance at the manometer 6corresponds to its pressure, and the resistance at the thermometer 7corresponds to its temperature. Thus all of the factors showing theamount of nected between the. oints 11 and 12, which f the two pairs ofarms.

are the junctions o v The first mentioned arm is from the point 8through the resistance andthe wire 10 to'the point 11; the second arm isfrom the point 8 through the manometer resistance 6, the

thermometer resistance 7 and the wire 13'to one end of a rheostat 14.The resistance of this rheostat is varied by moving an arm 15,

- which is the pointer. of the indicating device,

so causing a traveling contact 16 to move along therheostat andanarcuate conductor 17 which is connectedto the point 12 by a wire 19leading from the end 18. When the resistance of the rheostat 14, addedto the resistances 6 and 7, bears to the resistance 5 the same ratiothat the resistances joining at 9 bear to one another, there will- 'be'no" current through the galvanometer. 1

Current for the Wheatsone bridge is supplied from the generator 20, onemain lead comprising the wire 21 to the point 9, and the other the wire22 to the point 8. Inorder that-this generator may produce a constantvoltage, it is preferably driven by a. motor 57 of the constant speedtype. The same constant speed motor operates through a train ofreduction gearing 58 a cam 59 which at regular intervals causes thecontact device 25 to be lifted. This contact device has a pairofupstanding projections 26, one on each.

side of the ivot by which the device is connested-to t e lifting means.The rotating part of the galvanometer carries an arm 27 which presentstwo obstacles 28 of slightly greater spacin than the projections 26. Ifno current is owing through the galvanom eter, the arm 27 will be in itscentral position and both of the pro 'ections 26 .will hit obstacles 28so that the device 25 is not tilted about its pivot. If, however,current is flow.-

ing through the galvanometer so that the arm 27 is not in the centralposition, one of these projections 26 will escape its obstacle, whilethe other will contact with its obstacle, with" the result that theupward motion of the switch 25 will cause it to tilt about the pivot.

The tilting action of the switch 25 will cause it to engage a centralcontact 30 and one of the outside contacts 31 or 32. The

, When the pole changer is tilted to the left, so that the contacts30'and 31 are engaged by two sides of the switch member 25 are insulatedfrom one another, and the connections are such that these two sides,with the three contacts 30, 31 and 32, constitute a pole changer.

the arm, current will flow from the power line 23 through the wire 33-44to the contact 31, over the left hand member of the switch to the wire35, thence throu h the field 36 of the line 24. If the current throughthe galvanometer is in the other direction so that the arm 27 moves inthe other direction so that the switch 25 tilts to the right and engagesthe contacts 30 and 32, current will flow from the power line 23 overthe wires 33 and 42 to the contact 32, hence up the right hand one ofthe members of the switch 25, through I the wire 38 wire 37, field 36,wire 35, the left hand one of the members of the switch 25, the

contact 30, the wire 39, armature 40, wire 41 to the other power line34.

It will thus be seen that the current through the field 36 is in onedirection or the other according to the direction of the current throughthe galvanometer, and that when no current flows through thegalvanometer, no current will be supplied to the motor of the indicator.The arm 15 therefore rotates in "one direction or the other if at themoment the member 25 is lifted there is current flowing through thegalvanometer. The arm 15 makes contact'both with the rheostat 14 andwith the arcuate conductor 17, so that as it is moved in one directionor the other it increases or diminishes the resistance in that arm ofthe Wheatstone bridge containing the manometer 6, thermometer 7 andrheostat 14. It will thus be seen that the action of the indicatingdevice is to automatically adjust the rheostat 14 to a resistancethatgives no current in the galvanometer, and that this resistance is aflmction. of the pressure, tempera ture and velocity of the steam goingthrough the elbow.

To the foregoing electrical connections'l have added a system of motorsshown at 50, 51 and 52. One element of each of .these motors, preferablythe field is sup-' plied from the main line 23-24, over wires 53 and 54.One terminal of the other ele-" ment of each motor is connected to thewire 55, which joins the wire 35. The other terminal of each of theseelements is connected to the wire 56, which joins the wire 38.Preferably the element thus connected to the pole changer 25 is thearmature, but it may be either element as the designer desires, orifdesired the motors 50, 51 and 52 may be series motors so that bothelements are connected through the pole changer 25, as is the motor ofthe indicating device.

When the pole changer 25 moves toward the left, current flows from theline 23 over the wire 3334, contact 31, left hand part of the polechanger 25, wires 35 and 55, to the be small on this account. but may beof any.

' needed power. because the other element of these motors is connectedto the wires 53 and 5t directly to the power line. 'hen the pole changer25 is in the right hand position, current flows from the line 23 throughthe wire contact 32. right hand part of the pole changer 25. wires 35and 56. to the several motors in parallel. from whence it continues overthe wire 55 to the wire left hand part of the pole changer 25. contact30. wire 39. armature 40. wire 41. to the other line 24.

It will thus be seen that the pole changer 95 reverses the current inone of the elements of each of the motors 50. 51 and 52. but the.Current in the other elements of these motors is in a constantdirection. These motors therefore rotate in one direction or the other.according to the position of the pole changer 25. that is according tothe direction of the current in the galvanometer. and thatis accordingto the conditions in the elbow 1. The motors. therefore. are moved inaccordance with the velocity. the pressure and the tem perature of thesteam supplied by the boiler.

The motor 50. as seen near the upper part of Figure 1. controls a valvefor regulating the supply of feed water to the boiler. The motor 51, asseen at the right of Figure 1. controls a valve 51 which regulates thesupply of steam or other power to the engine which drives the endlessgrate or other form of mechanical stoker shown at 5- The motor 5:? isshown in dotted lines in the bottom of Figure 1. It controls the damper55. by which the admission of air to the furnace is regulated. Thus theindicating device. which is sensitive to the quantity and condition ofsteam delivered by the boiler. is made to automatically control thesupply of feed water to the boiler. the supply of coal to the furnaceand the supply of air to the furnace.

Under ordinary conditions. only one other regulation is needed in themanagement of a boiler. This is indicated by the damper 56, whichregulates the exit of flue gases from the furnace. I have discovered.that the conditions governing the difference in air pressure between theentrance point 55 of the furnace and the chimney depend on many othercont itions besides the velocity. pressure and temperature of the steamdelivered by the boiler. For this reason I have not provided a motorgoverned by the indicating device control the said motors.

and pole changer 25 to operate the damper 56. This damper may beoperatedmanually or may be provided with any desired automatic means.one. for example, responsive to the temperature within the fire boxmay'be used to control this motor.

I am aware that many changes may be made and numerous details ofconstruction may be varied through a wide range without departing fromthe principles of this invention. and I therefore do not purposelimiting the patent granted hereon otherwise than he cessitated by theprior art.

I claim as my invention:

1. In combination. a boiler. means for con trolling the supply of fuel.air and feed water tovsaid boiler. motors for operating said c011-trolling means. and an indicating and controlling device for governingthe operation of said motors. said device being responsive to thequantityand condition of steam supplied by said boiler.

:2. In combination. a boiler. means for controlling the supply of fuel.air. and feed water to the boiler. motors for operating said controllingmeans. electric circuit means responsive to the quantity and conditionof the steam; supplied by the boiler. a pole changer in operativeassociation with the electric circuit means to govern the operation ofthe motors. and an indicator in circuit association' with the polechanger and governed thereby.

3. In combination. a boiler. means for controlling the supply of fuel.air and feed water to said boiler. motors for operating said controllingmeans. a 'heatstone bridge circuit responsive to the quantity andcondition of the steam supplied to the boiler. a galvanoineterresponsive to unbalancing of the heatstone bridge circuit. a polechanger in operative association with the galvanometer to a rheostatforming the balancing resistance of the 'heatstone bridge circuit. andmeans whereby the pole changer controls the rheostat to balance thebridge circuit.

In testimony whereof I have hereunto subscribed my name.

JOHN? A. WIEXER.

